1. Field of the Invention
The present invention relates to an automotive traction control system and, more particularly, to an automotive traction control system capable of preventing the excessive slip of the vehicle in starting or accelerating the vehicle on a slippery road.
2. Description of Background Art
An automotive traction control system has previously been proposed to prevent the excessive slip of a vehicle by detecting a slip level on the basis of the respective rotating speeds of the driving wheel and the free wheel of the vehicle and suppressing the traction of the vehicle by regulating ignition timing and throttle opening. Such an automotive traction control system is disclosed in, for example, Japanese Patent Laid-open (Kokai) No. Sho 63-20253.
In case failure occurs in this known automotive traction control system during traction control operation, the automotive traction control system restores a normal running state.
If failure occurs in the traction control unit of the automotive traction control system while the traction is decreased to a relatively low extent, the vehicle may undergo a shock because the relatively low traction is increased instantly to the normal traction.